feat: verify address

BDKSwiftExampleWallet.xcodeproj/project.pbxproj

@@ -137,6 +137,7 @@
 		AE4984882A1BBBD8009951E2 /* BDKSwiftExampleWalletTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = BDKSwiftExampleWalletTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		AE49848C2A1BBBD8009951E2 /* BDKSwiftExampleWalletTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BDKSwiftExampleWalletTests.swift; sourceTree = "<group>"; };
 		AE4984A52A1BBCB8009951E2 /* README.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
+		AE6474732CE559E000A270C6 /* BDKSwiftExampleWallet.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = BDKSwiftExampleWallet.entitlements; sourceTree = "<group>"; };
 		AE6715F92A9A9220005C193F /* BDKSwiftExampleWalletPriceServiceTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BDKSwiftExampleWalletPriceServiceTests.swift; sourceTree = "<group>"; };
 		AE6715FC2A9AC056005C193F /* PriceServiceError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PriceServiceError.swift; sourceTree = "<group>"; };
 		AE6715FE2A9AC066005C193F /* FeeServiceError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FeeServiceError.swift; sourceTree = "<group>"; };
@@ -387,6 +388,7 @@
 		AE49847A2A1BBBD6009951E2 /* BDKSwiftExampleWallet */ = {
 			isa = PBXGroup;
 			children = (
+				AE6474732CE559E000A270C6 /* BDKSwiftExampleWallet.entitlements */,
 				AE11D5EB2B784B2900D67366 /* Info.plist */,
 				AE1C34222A424440008F807A /* App */,
 				AE7F670A2A7451B600CED561 /* Model */,
@@ -854,6 +856,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
+				CODE_SIGN_ENTITLEMENTS = BDKSwiftExampleWallet/BDKSwiftExampleWallet.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_ASSET_PATHS = "\"BDKSwiftExampleWallet/Preview Content\"";
@@ -862,6 +865,7 @@
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = BDKSwiftExampleWallet/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = "BDK Wallet";
+				INFOPLIST_KEY_NFCReaderUsageDescription = "We need NFC access to verify addresses.";
 				INFOPLIST_KEY_NSCameraUsageDescription = "\"To scan QR codes\"";
 				INFOPLIST_KEY_UIApplicationSceneManifest_Generation = YES;
 				INFOPLIST_KEY_UIApplicationSupportsIndirectInputEvents = YES;
@@ -887,6 +891,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
+				CODE_SIGN_ENTITLEMENTS = BDKSwiftExampleWallet/BDKSwiftExampleWallet.entitlements;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
 				DEVELOPMENT_ASSET_PATHS = "\"BDKSwiftExampleWallet/Preview Content\"";
@@ -895,6 +900,7 @@
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = BDKSwiftExampleWallet/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = "BDK Wallet";
+				INFOPLIST_KEY_NFCReaderUsageDescription = "We need NFC access to verify addresses.";
 				INFOPLIST_KEY_NSCameraUsageDescription = "\"To scan QR codes\"";
 				INFOPLIST_KEY_UIApplicationSceneManifest_Generation = YES;
 				INFOPLIST_KEY_UIApplicationSupportsIndirectInputEvents = YES;

BDKSwiftExampleWallet/BDKSwiftExampleWallet.entitlements

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.developer.nfc.readersession.formats</key>
+	<array>
+		<string>TAG</string>
+	</array>
+</dict>
+</plist>

BDKSwiftExampleWallet/Info.plist

@@ -5,8 +5,6 @@
 	<key>ITSAppUsesNonExemptEncryption</key>
 	<false/>
 	<key>NSPasteboardUsageDescription</key>
-	<string>&quot;To allow users to copy and paste text between the app and other apps&quot;</string>
-	<key>NSCameraUsageDescription</key>
-	<string>&quot;To scan QR codes&quot;</string>
+	<string>"To allow users to copy and paste text between the app and other apps"</string>
 </dict>
 </plist>

BDKSwiftExampleWallet/View Model/Receive/ReceiveViewModel.swift

@@ -6,13 +6,16 @@
 //
 
 import BitcoinDevKit
+import CoreNFC
 import Foundation
 import Observation
 
 @Observable
-class ReceiveViewModel {
+class ReceiveViewModel: NSObject, NFCNDEFReaderSessionDelegate {
     let bdkClient: BDKClient
 
+    private var nfcSession: NFCNDEFReaderSession?
+
     var address: String = ""
     var receiveViewError: AppError?
     var showingReceiveViewErrorAlert = false
@@ -35,3 +38,83 @@ class ReceiveViewModel {
     }
 
 }
+
+extension ReceiveViewModel {
+    func startNFCSession() {
+        guard NFCNDEFReaderSession.readingAvailable else {
+            receiveViewError = .generic(message: "NFC not available on this device")
+            showingReceiveViewErrorAlert = true
+            return
+        }
+
+        nfcSession = NFCNDEFReaderSession(
+            delegate: self,
+            queue: nil,
+            invalidateAfterFirstRead: false
+        )
+        nfcSession?.alertMessage = "Hold your iPhone near the Coldcard to verify the address"
+        nfcSession?.begin()
+    }
+
+    // MARK: - NFCNDEFReaderSessionDelegate
+
+    func readerSession(_ session: NFCNDEFReaderSession, didDetect tags: [NFCNDEFTag]) {
+        guard let tag = tags.first else {
+            return
+        }
+
+        session.connect(to: tag) { error in
+            if let error = error {
+                session.invalidate(errorMessage: "Connection error: \(error.localizedDescription)")
+                return
+            }
+
+            let payload = NFCNDEFPayload(
+                format: .media,
+                type: "text/plain".data(using: .utf8)!,
+                identifier: Data(),
+                payload: self.address.data(using: .utf8)!
+            )
+
+            let message = NFCNDEFMessage(records: [payload])
+
+            tag.writeNDEF(message) { error in
+                if let error = error {
+                    session.invalidate(errorMessage: "Write failed: \(error.localizedDescription)")
+                } else {
+                    session.alertMessage = "Address passed to Coldcard successfully"
+                    session.invalidate()
+                }
+            }
+
+        }
+    }
+
+    func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error) {
+        if let nfcError = error as? NFCReaderError,
+            nfcError.code == .readerSessionInvalidationErrorUserCanceled
+        {
+            return
+        }
+
+        DispatchQueue.main.async {
+            self.receiveViewError = .generic(message: error.localizedDescription)
+            self.showingReceiveViewErrorAlert = true
+        }
+    }
+
+    func readerSessionDidBecomeActive(_ session: NFCNDEFReaderSession) {
+        // Required delegate method, but no action needed when session becomes active
+    }
+
+    func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage]) {
+        if let message = messages.first,
+            let record = message.records.first,
+            let payload = String(data: record.payload, encoding: .utf8)
+        {
+            // Handle response
+        }
+        session.invalidate()
+    }
+
+}

BDKSwiftExampleWallet/View/Receive/ReceiveView.swift

@@ -6,6 +6,7 @@
 //
 
 import BitcoinUI
+import CoreNFC
 import SwiftUI
 
 struct ReceiveView: View {
@@ -51,6 +52,13 @@ struct ReceiveView: View {
                 )
                 .padding()
 
+                Button {
+                    viewModel.startNFCSession()
+                } label: {
+                    Image(systemName: "wave.3.right")
+                        .foregroundColor(.primary)
+                }
+
                 HStack {
                     Button {
                         UIPasteboard.general.string = viewModel.address